1. Field of the Invention
The present invention relates to a sheet conveying apparatus with a conveying path changing means and a sorter, and more particularly it relates to a sheet treating apparatus (sorter) having a function for sorting voluntarily and conveying sheets into a plurality of trays and an image forming apparatus.
2. Related Background Art
Recently, in image forming apparatuses such as copying machines, printers, facsimiles and the like, a sheet treating apparatus in which sheets are fed to the image forming apparatus and/or sheets on which image were recorded are sorted voluntarily into a plurality of trays and discharged or stapled has been used.
Such a technique was devised for the reason that, in an image forming apparatus such as a network printer which are used by plural persons, if a large number of sheets on which image were recorded are discharged onto a single tray, since it is difficult to discriminate who requires respective sheets in a sheet bundle discharged and stacked on the tray, the imaged sheets can be voluntarily sorted into a plurality of trays to assort respective documents. Among such conventional sheet treating apparatuses, for example, there is a sorter device in which sheets conveyed from a main body of an image forming apparatus are received and the received sheets are voluntarily sorted into a plurality of discharge trays to stack the sheets on the trays while conveying the sheets through a common sheet conveying path (common conveying path). As is well known, such a sorter device is used to be connected to a middle speed or high speed copying machine for mainly copying the same document by plural parts or a large size printer for printing a large number of sheets.
More specifically, for example, there is a sheet treating apparatus (sorter) of type in which discharge trays are fixed. Such a sheet treating apparatus comprises a plurality of discharge trays, a convey guide in which a plural pairs of discharge rollers for discharging sheet onto respective discharge trays are fixed to a main body of the apparatus and which defines a common conveying path and defines branch paths for guiding the sheets from the common conveying path to areas where the respective pair of discharge rollers are disposed, changing means (changing flappers) for voluntarily switching a conveying direction of each sheet at brunch paths of the common conveying path, and solenoids for driving the changing flappers. By one of the plural flappers simultaneously driven by a single actuating means through connecting means and elastic members, each sheet is sorted and is guided to a desired tray. If the flapper used for sorting the sheet is a downstream flapper among the flappers simultaneously driven, since flappers upstream of the downstream flapper abut against the sheet being conveyed, the common conveying path is not blocked by the upstream flappers.
However, in the conventional sorter, there are many unstable factors such as the facts that the plurality of flappers are driven simultaneously, that the flappers are driven via the elastic members, and that there is a case in which some flappers abut against the sheet and a case in which no flappers abut against the sheet. Thus, there is need for providing means for completing the oscillating movements of the flappers reliably and for ensuring that the sheet is discharged on the desired tray.